Swing Hacks

Make Text Components Searchable #48

Chapter 7, Text

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259

HACK

nothing tricky here. The complexity lies in the runNewSearch( ) function,

which handles the actual searching.

Running the Search

The runNewSearch( ) method pulls out the query string from the document.

Notice that it passes

0 and the length of the document into the getText( )

method. All of the Document methods operate in terms of a starting and end-

ing index. You deal with chunks of text only with these indices rather than

getting and setting

Strings, which would entail lots of byte copying. Copy-

ing isn’t a big deal for this hack, but it could be a problem for large docu-

ments (think several hundred kilobytes). Here is the

runNewSearch( )

method:

protected Matcher matcher;

private void runNewSearch(Document query_doc) {

try {

String query = query_doc.getText(0,query_doc.getLength( ));

Pattern pattern = Pattern.compile(query);

Document content_doc = content.getDocument( );

String body = content_doc.getText(0,content_doc.getLength( ));

matcher = pattern.matcher(body);

continueSearch( );

} catch (Exception ex) {

p("exception: " + ex);

ex.printStackTrace( );

}

}

After getting the text, runNewSearch( ) creates a new pattern from the query

(which requires no modification since it is a simple search), and then

retrieves the target document and text. With the search text, target body

text, and pattern in hand, it creates a

Matcher and calls